<!DOCTYPE html>
<meta charset="utf-8">
<meta property="og:image" itemprop="image primaryImageOfPage" content="https://hajimehoshi.github.io/ebiten/images/examples/infinitescroll.png">
<meta name="description" content="Ebiten example - infinitescroll">
<link rel="shortcut icon" href="../favicon.png" type="image/png" >
<link rel="icon" href="../favicon.png" type="image/png" >
<title>Ebiten example - infinitescroll</title>

<link rel="stylesheet" href="../stylesheets/bootstrap.min.css">
<link rel="stylesheet" href="../stylesheets/highlight-github.css">
<link rel="stylesheet" href="../stylesheets/ebiten.css">
<script src="../scripts/googleanalytics.js"></script>

<nav class="navbar"><div class="container">
  <nav class="d-flex flex-row" style="width: 100%;">
    <div class="nav mr-auto"><a class="navbar-brand" href="../"><img src="../images/logo_white.svg" alt="EBITEN"></a></div>
    <ul class="nav">
      <li class="nav-item"><a class="nav-link" href="https://github.com/hajimehoshi/ebiten">GitHub</a></li>
      <li class="nav-item"><a class="nav-link" href="https://godoc.org/github.com/hajimehoshi/ebiten">GoDoc</a></li>
      <li class="nav-item"><a class="nav-link" href="https://github.com/hajimehoshi/ebiten/wiki">Wiki</a>
      <li class="nav-item"><a class="nav-link" href="https://ebiten-playground.github.io/">Playground</a>
    </ul>
  </nav>
</div></nav>

<main><div class="container">

  <h2>Ebiten example - infinitescroll</h2>
  <iframe src="infinitescroll.content.html" width="640" height="480"></iframe>
  <div class="card"><pre class="card-body"><code class="language-go">// &#43;build example

package main

import (
        &#34;fmt&#34;
        _ &#34;image/png&#34;
        &#34;log&#34;

        &#34;github.com/hajimehoshi/ebiten&#34;
        &#34;github.com/hajimehoshi/ebiten/ebitenutil&#34;
)

const (
        screenWidth  = 320
        screenHeight = 240
)

var (
        bgImage *ebiten.Image
)

func init() {
        var err error
        bgImage, _, err = ebitenutil.NewImageFromFile(&#34;_resources/images/tile.png&#34;, ebiten.FilterDefault)
        if err != nil {
                log.Fatal(err)
        }
}

var (
        theViewport = &amp;viewport{}
)

type viewport struct {
        x16 int
        y16 int
}

func (p *viewport) Move() {
        w, h := bgImage.Size()
        maxX16 := w * 16
        maxY16 := h * 16

        p.x16 &#43;= w / 32
        p.y16 &#43;= h / 32
        p.x16 %= maxX16
        p.y16 %= maxY16
}

func (p *viewport) Position() (int, int) {
        return p.x16, p.y16
}

func update(screen *ebiten.Image) error {
        theViewport.Move()

        if ebiten.IsRunningSlowly() {
                return nil
        }

        x16, y16 := theViewport.Position()
        offsetX, offsetY := float64(-x16)/16, float64(-y16)/16

        // Draw bgImage on the screen repeatedly.
        const repeat = 3
        w, h := bgImage.Size()
        for j := 0; j &lt; repeat; j&#43;&#43; {
                for i := 0; i &lt; repeat; i&#43;&#43; {
                        op := &amp;ebiten.DrawImageOptions{}
                        op.GeoM.Translate(float64(w*i), float64(h*j))
                        op.GeoM.Translate(offsetX, offsetY)
                        screen.DrawImage(bgImage, op)
                }
        }

        ebitenutil.DebugPrint(screen, fmt.Sprintf(&#34;FPS: %0.2f&#34;, ebiten.CurrentFPS()))
        return nil
}

func main() {
        if err := ebiten.Run(update, screenWidth, screenHeight, 2, &#34;Infinite Scroll (Ebiten Demo)&#34;); err != nil {
                log.Fatal(err)
        }
}
</code></pre></div>

</div></main>

<footer><div class="container">
  <p>© 2013 Hajime Hoshi</p>
  <p>Code is licensed under <a href="https://github.com/hajimehoshi/ebiten/blob/master/LICENSE">the Apache License 2.0</a>.</p>
  <p>The content of this page is licensed under <a href="https://creativecommons.org/licenses/by/4.0/">the Creative Commons Attribution 4.0 License</a>.</p>
</div></footer>

<script src="../scripts/highlight.pack.js"></script>
<script>hljs.initHighlightingOnLoad();</script>
